1. Field of the Invention
This invention relates to a display device and operation method thereof, utilized in information processing devices and information terminal devices such as computers and in audio visual equipment such as household televisions and video tape recorders, etc.
2. Description of Related Art
Increasing progress in reducing the size of information terminals such as computers has allowed these computers or information terminals to be carried to other locations and used. Along with reducing the size of these information terminals, the device for reproducing the information was a display device operating by means of a directly viewable cathode ray tube which was large in size and heavy. Display devices therefore shifted to use of liquid crystal displays which were thin, light weight and consumed less power therefore providing information terminals which were much easier and convenient to transport.
Further, increasing progress in the digitalization of for instance, audiovisual equipment and telephone circuits allowed information for reproduction on display devices such as information terminals, to also consist of multimedia information such as visual information from televisions, video tape recorders, electronic cameras and video telephones as well as the usual letter information from computers. (Hereafter, letter or character information and visual information are given a common term of image information.)
With the advent of multimedia information, the display devices had to cope with demands for larger screens and multimedia processing functions. These demands have focused even more attention on thin, light weight and low power liquid crystal displays.
On the other hand, even the largest liquid crystal displays have drawbacks such as that screen dimensions (dimensions of opposing corners) are at most a maximum of 21 inches and a narrow visual angle (range from which roughly the same image can be seen as from directly in front of the image of the display device).
However, the problem of a narrow viewing angle was resolved by moving the liquid crystal molecules horizontally in a lateral electrical field relative to the glass substrate to achieve a wide viewing angle. The need for an increased screen size was resolved by means of a plasma display panel utilizing luminous plasma and fluorescent material.
Therefore the liquid crystal display and plasma display panels became capable of displaying highly precise screen information even when used parallel to a table or floor surface.
Also household products such as television capable of showing multiple screens were proposed. Further, information terminals such as computers were proposed for simultaneously opening a plurality of windows on a single screen and then displaying various information on the respective windows.
Amidst this environment, the terminal devices of the conventional art changed from just individual use to joint use of information provided from the terminal devices. For instance, display devices were preferred for use at electronic conferences among businessmen from different locations or at conferences at once location.
However, in these display devices of the convention art, the main objective was showing multiple screens and was provided only to allow a plurality of people to view the single display from one direction and therefore was not suited for use by a plurality of people viewing the display from opposite directions.
Whereupon, methods for controlling the display direction of the image information and displaying the information so that people could utilize the respective screen from various directions were designed utilizing methods such as inverting the top and bottom of the image information displayed on a single display device or by utilizing a plurality of display devices.
A method for inverting the image information as described above was proposed in Japanese Laid-open Patent No. Hei 4-326152 (1992) and in Japanese Laid-open Patent No. Hei 7-175444 (1995).
The above mentioned method for inverting the image information displayed on a single display screen could not provide an angle suitable for viewing by a plurality of people at the same time so that the image information had to be inverted to an extent needed by the people watching the display, thus making operation difficult.
Further, the above mentioned method utilizing a plurality of display screens required a plurality of memory storage circuits and a plurality of display screens making the display device large and thus presenting problems in terms of size, weight and power consumption.
Accordingly, it is an object of the present invention to provide a display device for displaying a plurality of image information suitable for a plurality of people on a single screen configured for use by a plurality of people around the periphery of the horizontally installed display by utilizing a thin, light weight display device consisting of a liquid crystal display or plasma display panel.
It is a further object of this invention to provide an operation method to display a plurality of image information on a single display screen and to allow screens to be split up according to the number of users, so that no single user can monopolize the entire display device.
The display device of this invention is configured such that a plurality of image information is displayed on the horizontally installed display unit and each image screen that is displayed is made to face forwards and backwards for the users positioned around the display screen.
Further, the direction the image information screen faces and how the image information screens are split is set beforehand and the image information screen can be shifted even after information was once shown.
Accordingly, even if a plurality of users are using the display device, a single display device can be used by splitting the screens up to match the number of users without having to prepare a plurality of individual display devices.
Also, this horizontally installed display device receives externally provided image information, has a menu screen as a method for displaying a plurality of image information screens on the display screen, is configured to be capable of setting the number of split screens on the image information screen and the orientation of the image information screen being displayed, and finally is further configured to allow selection of image information that was input.
Consequently, the image information screen can be easily split into other screens when the need occurs due to a change in the number of users so that an ideal number of image information screens can constantly be provided to match the number of users.
Still further, since much image information can be shown on a plurality of image information screens, a large amount of information can be checked at one time and the orientation of the display device can be changed to display one""s own image information to another user in an opposite position, further allowing joint use of information.
Yet further, the display device is comprised of a plurality of operating means for displaying image information screens on the display device and splitting up the image information display screen so that when only one user is present he may use the display screen and when there is a change in the number of users, the information screen can be split up into additional screens so that a single display device can be utilized by a plurality of users.
Even further, the display device is comprised of an operation means to specify movement of the image information screen and an operation means to select the type of input image information on the image information screen so that direct instructions are sent to an image information screen needing a change, operating errors can be prevented and changes can be executed quickly.